White lead



UNITED STATES PATENT OFFICE.

NORMAN K. MORRIS AND JOHN W. BAILEY, OF DENVER, COLORADO.

WHITE LEAD.

SPECIFICATION forming part of Letters Patent No. 493,178, dated March 7,1893.

Application filed January 28, 1893. Serial No. 460,118. (No specimens.)

To all whom it may concern.-

Be it known that we, NORMAN K. MORRIS and JOHN W. BAILEY, both ofDenver, in the county of Arapahoe and State of Colorado, have invented acertain new and useful Improvement in White Lead, whereof the followingis a specification.

Ourinvention consists of a new type of the article commonly known in thearts as white lead, under which generic name are comprehended thevarious admixtures of lead, carbonate and hydrated lead oxide, used inconjunction With oil for painting purposes. As heretofore produced(usually by the well known Dutch process) white lead is obtained as acrude product in the form of solid flakes or scales of such cohesion asto require treat ment by grinding in order to prepare it for use in thearts; furthermore, it resists mixture with the oil which is to be itsvehicle, and such admixture needs to be effected by grinding theingredients together. Other processes are in use for the manufacture ofwhite lead by which the carbonic acid gas required for the corrodingprocess is obtained from the combustion of coke or charcoal. In these,the products of combustion are more or less contaminated with carbonicoxide, sulphurous acid, &c., producing an impure article which lacksbody, spreading and covering qualities, the product (as in the case ofthe Dutch method also) having but limited readiness for combining withthe oil necessary for its application as a paint.

The physical characteristics of the white lead of our invention are,first, extreme natural comminution and entire homogeneity, and, second,exceedingly intimate natural admixture with a minute quantity of avolatile oil, of the petroleumtype, which isinherently intermingled withthe individual particles. The percentage, or relative quantity, of thevolatile oil, thus present, may be, and preferably is, a mere film uponthe particles, and does not interfere with the apparent dryness of theproduct, although it modifies the actual condition thereof. The valuablequalities due to these physical characteristics, are, great freedom fromadhesiveness between the particles when in their dry and unmixed state,which prevents obstinate coherence in masses,

or caking, and insures ready disintegration without grinding; also greatavidity for combining or assimilating with oil (usually linseed) whichis to be the vehicle for application as a paint; alsoa vast increase ofcovering and spreading power and increased whiteness, as compared. withother analogous products.

We will now proceed to describe the preferred method of manufactureadapted to produce the white lead embodying our invention. We take leadfiber, or threads of metallic lead, form it into rolls withoutsubstantial compression, dip it in dilute acetic acid, permit thesurplus acid to drain out during an exposure to the air of say twentyminutes, and then place it in a corroding chamber of any well knownform. We then introduce into said chamber the products of combustion,and derivative or accompanying vapors, of crude petroleum or petroleumresidue, which we utilize preferably as follows: We take the crudepetroleum, or petroleum residue, and by means of a steam jet or anyconvenient device for atomizing or vaporizing it, we sprayit, inconjunction with steam, against an incandescent or highly heated surfacein a proper combustion chamber. We prefer to employ a limekiln for thispurpose, since incidentally the carbonic acid gas, driven off from thelime-stone, adds to the total volume of the corroding gas withoutimpairing the specific value of the products of combustion andderivatives or accompanying vapors of the hydro-carbon and decomposedsteam. The lime in a state of incandescence afiords a very efficientheating surface for decomposing the steam and cracking the hydro-carbonvoil and insures the thorough combustion of so much thereof as isdirectly consumed, thus securing-entire freedom from soot and preventingthe formation of carbonic oxide,which would in some degree reduce thehydrated lead oxide formed during the corroding process, and developminute spots or particles of metallic lead locally distributedthroughout the mass. The carbonic acid gas and the derivatives oraccompanying vapors resulting from the treatment to which the petroleumis subjected are cooled down and admitted, preferably at a temperatureof about 80 Fahrenheit, to the corroding chamber in which the leadpreviously treated, as described, by means of acetic acid, is exposed.Air is admitted in suitable quantities to insure proper combustion, aforced draft being preferably maintained by means of a blower interposedbetween the lime kiln or other combustion chamber and the corrodingchambers, and it will be understood that any suitable means for securingthe admission of air may be employed. \Ve find that under thesecircumstances, a very vigorous corrodi n g attack upon the lead takesplace, and that the particles of White lead formed are naturallycomminuted and thus require no grinding whatever, but are capable ofcollection in proper form for use by levigation alone. iVe further findthat the resultant product is characterized by the peculiar featureshereinbefore pointed out, which features permanently inhere in the whitelead.

Having thus described the white lead of our invention and the bestmethod known to us for producing it, we wish it to be understood that wedo not limit ourselves to a product which has been obtained by theprocess above set forth. \Vc believe that to obtain the article in thehighest degree of perfection it is desirable that all the componentsshould be of substantially con-nascent production, but as we are unableto state with absolute certainty the exact reactions which occur, weprefer to use in our claim the expression inherently commingled asdefining the condition of the solid particles and the volatile oil. Bythis We mean that such commingling is attendant upon, or an incident of,the corroding process as a whole.

We claim As a new composition of matter, a white lead consisting of leadcarbonate and hydrated lead oxide, in a naturally comminuted condition,and having its particles inherently commingled with a volatile oil ofthe petroleum type, substantially as set forth.

NORMAN K. MORRIS. JOHN W. BAILEY.

Witnesses as to the signature of Norman K. Morris:

JOSEPH W. HOWARD, H. R. MOGLELLAND.

iVitnesses as to the signature of John \V. Bailey:

S. M. J ANNEY, JAMES H. BELL.

